Liquid-to-gas indicator and actuator device

ABSTRACT

S LIQUID-TO-GAS INDICATOR IS DISCLOSED WHICH, IN ONE POSITION, WILL NORMALLY FLOW LIQUID AND WILL SENSE AND RESPOND TO THE BEGINNING OF GAS FLOW BY MOVING A MECHANICAL ACTUATING MEMBER WHICH MAY OPERATE A MICROSWITCH OR OTHER OUTPUT DEVICE. WHEN INVERTED, THE DEVICE WILL NORMALLY FLOW GAS BUT WILL RESPOND TO THE BEGINNING OF LIQUID FLOW BY MOVING THE ACTUATING MEMBER AS DESCRIBED. A SPRING-LOADED CHECK VALVE IS INSTALLED IN A MAIN CONDUIT WITH A FLOAT-TYPE BALL VALVE IN A PARALLEL CONDUIT CONNECTED ACROSS THE CHECK VALVE. A PISTON IS POSITIONED IN THE WALL BETWEEN THE CONDUIT SUCH THAT IT   RESPONDS TO CHANGES IN THE PRESSURE DIFFERENTIAL ACROSS THE CHECK VALVE AND THE ACTUATING MEMBER IS MOVED IN RESPONSE TO MOVEMENT OF THE PISTON. AN OPTIONAL BIASING SPRING IS PROVIDED URGING THE PISTON IN ONE DIRECTION, AND AN ADJUSTMENT SCREW IS PROVIDED FOR VARYING THE FLOW RATE OF THE PARALLEL CONDUIT.

United States Patent Inventor Leslie J. Dawes Van Nuys, Calif. Appl. No.873,047 Filed Oct. 31, 1969 Patented June 28, 1971 Assignee The BendixCorporation LlQUlD-TO-GAS INDICATOR AND ACTUATOR DEVICE 6 Claims, 1Drawing Fig.

11,8. Cl 91/419, 73/438, 73/451, 116/70 Int. Cl ..1"15b 11/08, F15b13/04 FieldofSearch 91/1,419,

415, 418; 73/451, 290, 438, (inquired); 340/(lnquired); 1 l6/(lnquired);33/(lnquired); 137/(1nquired); 89/1309, 1.81, 1.812, (inquired);

References Cited UNITED STATES PATENTS 3,001,512 9/1961 Cochin 91/4Primary Examiner-Martin P. Schwadron Assistant E,raminerlrwin C. CohenAttorneys-Plante, Arens, Hartz, Smith. and Thompson and Robert C SmithABSTRACT: A liquid-to-gas indicator is disclosed which, in one position,will normally flow liquid and will sense and respond to the beginning ofgas flow by moving a mechanical actuating member which may operate amieroswitch or other output device. When inverted, the device willnormally flow gas but will respond to the beginning of liquid flow bymoving the actuating member as described. A spring-loaded check valve isinstalled in a main conduit with a float-type ball valve in a parallelconduit connected across the check valve. A piston is positioned in thewall between the conduits such that it responds to changes in thepressure differential across the check valve and the actuating member ismoved in response to movement of the piston. An optional biasing springis provided urging the piston in one direction, and an adjustment screwis provided for varying the flow rate of the parallel conduit.

LilQlUlD-TO-Gdtfi INDICATOR AND ACTUATOR DEVICE BACKGROUND OF THEINVENTION in connection with launching of underwater devices such asinstruments from ships or submarines, a need has arisen for indicatingdevices which can tell an operator at any given time whether air orwater is in the launching tube and, preferably, which can respond to thechanged condition as the air purges all the water from the tube or asthe water displaces all the air to actuate some device forming part of alaunching mechanism. In the past, this operation has involved eithervisual observation of the condition or the launch tube or simply waitinga known period of time for purging to be completed, followed by manualoperation of the actuating means when it has been determined that thetube is purged either of water or of air. With current requirements formuch more data, it has been found desirable to provide means which willmake possible much faster automatic launching of devices into the water.Thus, there is a need for devices which will respond very quickly tocompletion of either of the purging operations described above in orderto trip a new step in the launching cycle.

DESCRIPTION OF THE DRAWING The single FIGURE is a sectional view of aliquid-to-gas indicator made according to my invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The single FIGURE shows ahousing at numeral 10 which includes a principal axial conduit 12 withan inlet passage l4 and an outlet passage l6. Positioned in conduit ll2is a check valve llil which is urged against a seat 20 by means of aspring 22. A retainer 24 is held in the lower end of conduit 12 by meansof a set screw 26.

Connected in parallel with conduit 12 across the check valve W is a pathconsisting of a passage 23, a valve seat 30 which cooperates with a ballfloat valve mcmber'32, and a port 34 leading to a chamber 36 which, inturn, communicates with a port 36 leading to passageway 40 connectedinto conduit I12 downstream of the check valve 16. A manually adjustablevalve member 42 is provided for varying the flow rate of the conduit 40.

A cylindrical opening 44 is formed between chamber 36 and conduit l2,and in this opening is placed a piston 46 which is spring loaded towardthe right by means of a spring 48. This spring is carried on a smallerdiameter section 49 extending from each face of piston 46. An actuatingmember 50 is formed as an extension of section 49 and is shown as asimple rod movable axially with piston 46 and which may be used tooperate a microswitch or other indicating device in response to movementof piston 46. A plug member is installed in housing H ll for the purposeof retaining a seal 52 around actuating member :17.

A retainer member 33 is provided to close one end of chamber 36 and toact as a retainer for spring 46. An additional plug member 54, which maybe threadedly engaged with housing llfl, is provided to permitinstallation, inspection and replacement of ball float valve 32.

In considering the operation of the device above described, it willfirst be assumed that water or other liquid is being supplied to inletport 14 under sufficient pressure to open the checlt valve 116 such thatit will flow through the housing and out of outlet port 16. During suchtime the liquid will also enter passage 26, will float the ball valvemember 32 off its seat 30, will flow past port 34 into chamber 36, pastport 38, through passage 40, and into the lower end of conduit 12. Underthese conditions, the fluid pressure acting on both faces of piston 46is substantial and nearly equal, with the force acting on a slightlylarger effective area tending to force piston 46 to the right. To ensurethat piston 46 is maintained in this position, the spring 48 is suppliedto provide a further biasing force in this direction. Since theoperating areas may be care- LII fully controlled, the use of the spring48 is not absolutely required, but it will simplify calibration of thedevice, When the flow through the housing 10 ceases to be liquid andbegins to be a gas, the pressure will continue to be sufficient to keepcheck valve 18 off its seat, but the ball float valve 32 will bepositioned on its seat 30. As a result, there is a substantial drop inthe pressure in chamber 36, and the pressure differential acting acrosspiston 46 will be sufficient to move this piston and the associatedmembers, including actuator 50, to the left against the force of spring46. As indicated above, the actuating member 50 will typically operate amicroswitch which may then initiate a launching process.

When the device is used to operate the actuating member 50 in responseto a change from gas to liquid flow, it will be installed in invertedposition but with passage l4 still operating as the inlet passage. Underthese conditions the gas supplied to conduit l2 will force check valve18 off of seat 20 against the action of spring 22, and this gas willflow directly through conduit l2 and out of outlet passage 16. Also, thefloat member 32 will remain in the position shown through gravitationalforce, thus allowing gas to flow across seat 30, into chamber 36, acrossport 33, passage 40, and into the lower end of conduit 12. Here again,the fluid forces acting on the opposite sides of piston 46 tend to biaspiston 46 toward the position shown with the spring 48 serving toadditionally bias piston 46 toward the position illustrated. When liquidappears at conduit 12, it will act to float ball valve 32 against theseat 30, resulting in reducing the fluid pressure in chamber 36 substantially below that in conduit 12, thereby causing piston 46 and itsassociated parts to move to its opposite position.

As indicated above, the valve member 42 which acts to control the flowrate of passageway 40 may or may not be required in a given application.It has been shown as a useful means for providing a threshold adjustmentfor the device. Similarly, spring 48 may not be an absolute requirementin all installations, but it will be appreciated that somewhat more carewill be required in connection with the balancing of effective areas ofpiston 46 if spring 46 is not used. Other modifications will be obviousto those skilled in the art in that while member 46 has been shown as a.piston with spring-biasing means, an essentially identical functioncould be provided by means of a bellows or even a diaphragm device if ithas sufficient travel. Such members as retainer 24 and the plug members51 and 53 may obviously be retained by means other than those shown.

lclaim:

l. A liquid-to-gas indicator and actuator comprising:

a housing having an inlet port, an outlet port, a first fluid flowconduit connecting said ports, a check valve in said conduit, andresilient means urging said check valve in a direction to block flowthrough said conduit;

a second fluid flow conduit in said housing connected in parallel withsaid check valve including a valve seat in communication with said firstconduit upstream of said check valve, a ball float valve in said secondconduit operative with said seat to close said second conduit; said ballfloat valve being of such density that it will float in a liquid butwill not float in a gas;

movable wall means midstream of said checlt valve and said float valveand in communication with said first and second conduits including meansurging said movable wall means toward said first conduit when said ballfloat valve is not seated;

and an actuating member operatively connected to said movable wallmeans.

2. A liquid-to-gas indicator and actuator as set forth in claim Iwherein an adjustment means is provided for varying the flow rate ofsaid second conduit downstream of said ball float valve.

3. A liquid-to-gas.indicator as set forth in claim I wherein said meansurging said movable wall means includes resilient means.

s. A liquid-to-gas indicator as set forth in claim ll wherein saidactuating member is a rod connected to said movable wall means.

5. A liquid-to-gas indicator as set forth in claim 3 wherein saidmovable wall means includes a piston and said resilient means includes aspring.

6. A liquid-to-gas indicator and actuator comprising:

a housing having an inlet port, an outlet port, a first fluid conduitconnecting said ports, a check valve in said conduit and a springyieldably urging said check valve in a direction to close said conduit;

a second fluid flow conduit in said housing providing communicationbetween said ports and connected to said first fluid flow conduit inparallel with said check valve,

a valve seat in said second conduit and a ball float valve memberoperative with said seat to close said second conduit said ball floatvalve being of such density that it will float in a liquid but will notfloat in a gas;

a movable wall device in said housing having one side thereof exposed tothe fluid pressure in said first fluid conduit upstream of said checkvalve and an opposing side thereof exposed to the fluid pressure in saidsecond conduit downstream of said check valve, and spring means urgingsaid movable wall device toward said first fluid conduit;

and an actuating member operatively connected to said movable wallmeans;

whereby when said housing is maintained in a first position and liquidis supplied to said inlet port said ball float valve member floats offits seat permitting liquid to impinge against both sides of said movablewall device and retaining said actuating member in a first position, andwhen gas is supplied to said inlet port said ball valve is seated on itsseat resulting in a reduced pressure in said second conduit and saidmovable wall device moves said actuating member to a second position;and

when said housing is inverted and gas is supplied to said inlet port,said ball valve member drops away from its seat, permitting the pressureof said gas to be applied against both sides of said movable wall deviceretaining said actuating member in said first position, and when liquidis supplied to said inlet port, said ball valve floats against its seatresulting in a reduced pressure in said second conduit and said movablewall device moves said actuating device to said second position.

